1. Field of the Invention
This invention relates to control apparatus responsive to liquid flow.
2. Description of the Prior Art
It has heretofore been proposed to provide liquid level responsive devices located in a tank so that when the level in the tank reaches a predetermined low level a control signal is available.
It has also heretofore been proposed to provide pressure responsive switches in a flow line but these have various shortcomings including problems of sealing and packing and lack of quick response to changes in conditions.
Receptacles for liquid chemicals and the like are now frequently employed in which the contents are not intended to be exposed to the air and the receptacle is collapsed as the liquid is withdrawn. The size of such receptacles and their delivery openings does not permit of the insertion of level responsive apparatus into the receptacle. It is also not desired to provide air or gas replacement as the liquid is withdrawn.
It is the principal object of the invention to provide control apparatus responsive to liquid flow which includes a float operated switch with a pressure operated element for moving the float under certain pressure conditions.
It is a further object of the invention to provide control apparatus of the character aforesaid which is particularly suited for use but is not limited for use with a closed liquid system.
It is a further object of the invention to provide control apparatus responsive to liquid flow which comprises a float operated magnetically actuated switch with a pressure controlled override of the buoyant action of the float.
It is a further object of the invention to provide control apparatus responsive to liquid flow which comprises a float operated switch with an expansible chamber providing a control element which chamber acts to equalize pulses from the liquid.